boundary

noun

1. 1

   The dividing line or location between two areas.

2. 2

   (often in the plural) The bounds, confines, or limits between immaterial things (such as one’s comfort zone, privacy, or professional sphere and the realm beyond).

3. 3

   An edge or line marking an edge of the playing field.

4. 4

   An event whereby the ball is struck and either touches or passes over a boundary (with or without bouncing), usually resulting in an award of 4 (four) or 6 (six) runs respectively for the batting team.

5. 5

   (of a set) The set of points in the closure of a set S, not belonging to the interior of that set.